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Describes an elastic visco‐plastic finite element formulation that is applied to the modelling of pastes. Comparisons are made with experimental results obtained for a particular paste, plasticine. Special attention is applied to the frictional boundary conditions, for which the usual Coulombic procedure is augmented by a “cohesive” wall friction component. Viscous effects also are considered.

As known from nearly incompressible elasticity, selective reduced integration (SRI) is a simple and effective method of overcoming the volumetric locking problem in 2D and 3D solid elements. This method of finite elastoviscoplasticity is discussed as are its well‐known limitations. In this context, an isochoric‐volumetric decoupled material behavior is assumed and thus the additive deviatoric‐volumetric decoupling of the consistent algorithmic moduli tensor is essential. By means of several numerical examples, the performance of elements using selective reduced integration is demonstrated and compared to the performance of other elements such as the enhanced assumed strain elements. It is shown that a minor modification, with little numerical effort, leads to rather robust element behaviour. The application of this process to so‐called solid‐shell elements for thin‐walled structures is also discussed.

Engineers have developed robust and efficient incompressible finite element formulations using tools such as the Patch Test and the counting of constraints/variables, the first one aimed at the development of consistent elements and the second one aimed at the development of non‐locking and stable elements. The mentioned tools are rooted in the physics of the continuum mechanics problem. Mathematicians, on the other side, developed complex and powerful tools to examine the convergence of finite element formulations, such as the inf‐sup condition, these methods are based on the properties of the elliptical PDEs that constitute the mathematical model of the continuum mechanics problem. In this paper we intend to understand the inf‐sup condition from an engineering perspective, so as to be able to incorporate it into the package of tools used in the development of finite element formulations.

Elasto‐plastic models based on critical state formulations have been successful in describing many of the most important features of the mechanical behaviour of soils. This review paper deals with the applications of this class of models to the numerical analysis of geotechnical problems. After a brief overview of the development of the models, the basic critical state formulation is presented together with the main modifications which have actually been used in computational applications. The problems associated with the numerical implementation of this type of models are then discussed. Finally, a summary of reported computational applications and some specific examples of analyses of geotechnical problems using critical state models are presented.

A derivation for the finite element equations of consolidation by the principle of virtual work and virtual complementary work is presented. This provides a simple alternative to derivation by variational principles or the Laplace transform. In the final part of the paper the equations are rearranged into a form suitable for time stepping for non‐linear applications.

The purpose of this paper is to give an explanation of the new data available about surface subsidence above the depleted gas reservoir Ravenna Terra. These data confirm the existence after end of exploitation of a reversed subsidence bowl with minimum subsidence above the reservoir, as opposed to conventional subsidence bowls during exploitation which show maximum subsidence in the same location.

The paper analyses these new data about the existence after end of exploitation of a reversed subsidence bowl. The observed behaviour is reproduced successfully with a fully coupled two phase flow code in deforming reservoir rocks which incorporates a constitutive model for partially saturated porous media.

The paper provides successful simulations. These allow affirming with confidence that the explanation for the peculiar behaviour is reservoir flooding and partially saturated rock behaviour.

Further research: other case studies where similar behaviour is expected, e.g. Ekofisk.

The paper includes implications for better management of reservoir exploitation schedules to minimize the observed phenomenon.

This paper explains the peculiar behaviour of subsidence above the depleted gas reservoir Ravenna Terra and confirms the conjecture that constitutive behaviour of partially saturated rocks is the origin of the observed phenomenon.

This paper aims to determine the extent to which the strategy of Noken-Papuan products, known as intangible culture recognized by the United Nations Educational, Scientific and Cultural Organization (UNESCO), can increase local economic empowerment. The main strategy is to strengthen the regulation of the use of Noken in every activity of daily life while promoting it, this has not been explained much from previous research.

The study used the method of strengths, weaknesses, opportunities, and threats– analytic hierarchy process (SWOT-AHP) with analysing several pairs of instruments’ predetermined group and finally decision-making strategy recommendations. Data distribution to five districts of Jayapura using simple random sampling based on consideration type product and industrial areas with a number of elements in each sub-population are different.

The development of local products with cultural values is one of the important points included in the regional development strategy model.

The traditional handmade products that have a high cultural philosophical value can be beneficial to the local community empowerment.

Ethnotechnology can be well-developed and implemented if policy actors identify the values of external and internal factors to be formulated in enhancing local economic development. This work is a simple attempt to collect research findings separately on Noken product development as a conceptual basis for comparative analysis.

The paper aims to clarify the relationship between the micro-structures of porous media and the coefficient of permeability. Most materials involve different types of defects like caves, pores and cracks, which are important characters of porous media and have a great influence on the physical properties of materials. To study the seepage mechanical characteristics of damaged porous media, the constitutive model of porous media dealing with coupled modeling of pores damage and its impact on permeability property of a deforming media was studied in this paper.

The paper opted for an exploratory study using the approach of continuum damage mechanics (CDM).

The paper provides some new insights on the fluid dynamics of porous media. The dynamic evolution model of permeability coefficient established in this paper can be used to model the fluid flow problems in damaged porous media. Moreover, the modified Darcy's law developed in this paper is considered to be an extension of the Darcy's law for fluid flow and seepage in a porous medium.

Owing to the limitations of time, conditions, funds, etc., the research results should be subject to multifaceted experiments before their innovative significance can be fully verified.

The paper includes implications for the development of fluid dynamics of porous media.

This paper fulfils an identified need to study the relationship between the micro-structures of porous media and the coefficient of permeability.

Many practical problems in engineering require fast, accurate numerical results. In particular, in cyclic plasticity or fatigue simulations, the high number of loading cycles increases the computation effort and time. The purpose of this study is to show that the return mapping technique in the framework of unconventional plasticity theories is a good compromise between efficiency and accuracy in finite element analyses.

The accuracy of the closest point projection method and the cutting plane method implementations for the subloading surface model are discussed under different loading conditions by analyzing the error as a function of the input step size and the efficiency of the algorithms.

Monotonic tests show that the two different implicit integration schemes have the same accuracy and are in good agreement with the solution obtained using an explicit forward Euler scheme, even for large input steps. However, the closest point projection method seems to describe better the evolution of the similarity centre in the cyclic loading analyses.

The purpose of this work is to show two alternative implicit integration schemes of the extended subloading surface method for metallic materials. The backward Euler integrations can guarantee a good description of the material behaviour and, at the same time, reduce the computational cost. This aspect is particularly important in the field of low or high cycle fatigue, because of the large number of cycles involved.

A detailed description of both the cutting plane and closest point projection methods is offered in this work. In particular, the two integrations schemes are compared in terms of accuracy and computation time for monotonic and cyclic loading tests.

Gombe state in northeast Nigeria records a high prevalence of home deliveries with very low facility deliveries despite the efforts of government and international non-governmental organizations in supporting maternal health services. The purpose of this paper is to assess the factors influencing the decision to choose a birth center by pregnant women in Gombe, Nigeria.

The design was a cross-sectional study of women from a baseline survey conducted in August 2016 in Gombe state, Nigeria. Data on women groups’ utilization of maternal services with a focus on antenatal care, delivery and postnatal care were collected using a structured questionnaire used for household survey conducted in the state. Data for 157 pregnant women from the sample of 750 women (15–49 years) were selected for the purpose of this analysis. Descriptive statistics, bivariate and multivariate analyses were used to determine the factors associated with choice of birth center.

Religion (AOR=12.117, 95% CI 1.774–82.741), paid work (AOR=3.633, 95% CI 1.243–10.615) and identification and knowledge of pregnancy complications (AOR=4.281, 95% CI 1.054–17.387) were the factors found to be significantly associated with choice of birth center by pregnant women. Age, education, closeness to a facility and decision by husband or woman were not found to be statistically significant.

The significance of disseminating knowledge about pregnancy complications, role of religious leaders and encouraging savings from women earnings need attention of the government to improve facility-based delivery.